Assessment and modelling of the viability of a solar heating system for aquatic centres in southern Australia

Abstract

Aquatic centres are large users of energy for water and space heating with an energy intensity which can be up to seven times that of a commercial office building in Australia. Much of the energy is used to heat water to relatively low temperatures, and therefore, solar energy technology is capable of providing this energy. In the residential sector, solar thermal systems for heating water and swimming pools are well-established. This is not the case for commercial swimming pools i.e. aquatic centres. In Australia, a program to encourage commercial pool operators to install solar systems was funded in the early 1980s. This paper has investigated the current use of and attitudes to solar systems in commercial pools through a survey of municipal pool operators in Victoria, southern Australia. The survey found that there has been very little increase in the use of solar energy and that perceived barriers to the use of the technology remain the same as they were nearly 30 years ago. Lack of roof area, poor payback periods and an inability of solar to meet pool heating needs are the most common misconceptions. The paper investigates these misconceptions by analysing the hot water needs of a large aquatic centre in Melbourne. It was found that there was sufficient roof area to accommodate a solar system that would provide a solar fraction of 0.60 and the simple payback period for a solar system using unglazed solar collectors was approximately 6.7 years at current gas prices. These are predicted to rise significantly making solar energy an even more attractive proposition for commercial pool heating. Failure of past incentives to stimulate the uptake of solar pool heating systems necessitates a revised approach. Key stakeholders (industry bodies, local governments, pool operators, manufacturers, relevant HVAC consultants and research organisations) all need to be involved in an exemplar project to demonstrate the technology’s viability for aquatic centres.